In a previous work we obtained exact solutions for the proper time quantum mechanics of a thin dust shell, collapsing in a vacuum. We extend these results to the quantum collapse of a dust shell surrounding a preexisting black hole. In lieu of exact solutions, which have so far proved difficult to obtain for this system, we establish the essential features of the quantum shell through a Wentzel-Kramers-Brillouin

Wormhole solutions to the equations of general relativity have some spectacular local and global properties. As these unusual features are not explicitly forbidden by known physics, wormholes are considered in various astrophysical and cosmological scenarios. The paradigmatic traversable wormhole models are described by static spherically symmetric Ellis-Morris-Thorne and Simpson-Visser metrics. We show

Four researchers — Nicolas Bonne, Cheryl Fogle-Hatch, Garry Foran and Enrique Perez Montero — discuss the accessibility challenges in astronomy research, education and outreach for persons who are blind or visually impaired. Solutions to these challenges create innovative data analysis methods for all astronomers.

We propose a mapping between geometry and kinematics that implies the classical equivalence of any theory of massless bosons—including spin and exhibiting arbitrary derivative or potential interactions—to a nonlinear sigma model (NLSM) with a momentum-dependent metric in field space. From this kinematic metric we construct a corresponding kinematic connection, covariant derivative, and curvature, all

We discuss some aspects related to holography of anti–de Sitter (AdS) dyonic hairy black holes, which break the conformal symmetry of the boundary. We use counterterms for the scalar field that satisfies mixed boundary conditions to compute the Euclidean action and dual stress tensor. We apply these results to show that the Cardy-Verlinde formula is not satisfied. However, when the magnetic (or electric)

Astronomy needs ground- as well as space-based telescopes. The European Southern Observatory (ESO), an example of successful international cooperation, has managed state-of-the-art observatories for the past 60 years.

In this work we revisit the famous Fermi two-atom problem, which concerns how relativistic causality impacts atomic transition probabilities, using the tools from relativistic quantum information and algebraic quantum field theory. The problem has sparked different analyses from many directions and angles since the proposed solution by Buchholz and Yngvason [Phys. Rev. Lett. 73, 613 (1994)]. Some of